1. Field of the Invention
The present invention relates to a moisture-retentive cooling gel, a laminate thereof, and a moisture-retentive cooling plaster using such a gel or laminate.
2. Description of Related Art
Moisture-retentive cooling plasters have been known which include a support base and a gel layer such as of a water-soluble polymer provided on the support base. Such a moisture-retentive cooling plaster is superior in portability and adhesion, and used as a cooling medium for treatment of a feverish patient instead of an ice pack and an ice pillow.
The moisture-retentive cooling plaster, if its portability is an essential requirement, has a smaller water content because the size of the gel layer provided on the support base is limited. This leads to a shorter duration of moisture-retaining and cooling effects.
It is an object of the present invention to provide a moisture-retentive cooling gel, a laminate thereof, and a moisture-retentive cooling plaster, which offer moisture-retaining and cooling effects for a controlled duration and have superior functionality, e.g., capability of delivering and transporting an effective ingredient such as a pharmacological active ingredient or a perfume.
In accordance with a first aspect of the present invention, there is provided a moisture-retentive cooling gel which comprises: a water-retentive matrix of a water-soluble polymer having a water content of not lower than 4 wt %; and fibers dispersed in the water-retentive matrix, the fibers having a hydrophilic property at least at surfaces thereof, some of the fibers being exposed on a surface of the water-retentive matrix.
In accordance with a second aspect of the present invention, there is provided a moisture-retentive cooling gel laminate which comprises a plurality of layers of the aforesaid moisture-retentive cooling gel stacked one on another with a mesh sheet or a porous sheet interposed therebetween.
In accordance with a third aspect of the present invention, there is provided a moisture-retentive cooling plaster which comprises: an air-permeable support sheet; and the aforesaid moisture-retentive cooling gel or the aforesaid moisture-retentive cooling gel laminate provided on the support sheet.
The moisture-retentive cooling gel, the moisture-retentive cooling gel laminate and the moisture-retentive cooling plaster in accordance with the present invention each have a greater water content and a higher water vaporization rate and, therefore, sustainably offer superior effects when used as: (1) a medical cooling pad for cooling a part of a feverish human body; (2) a cooling package for fresh protection of fish, drinking water, liquor and the like in transportation thereof; (3) a cooling sheet for prevention of melting of chocolate in transportation thereof; (4) a pad for muscle cooling after sport and for skin care after sunburn; (5) a protective pad for water supply to a dry skin; and (6) a plaster containing an anti-inflammatory agent.